Course-protractor



J. F.' COLE.

COURSE PHOTRACTOR.

APPLICATION FILED'MAR. l5. 1918.

1,313,520. y PatentedAug.19,1919.

' extending the stud ll, there visjno danger.that` the ad; jusbment. it the compass member, l.will 'be upset when the nut 31 is tightened. Y

Surrounding the str rd` 11 is av member from which eXtendsthe `radius"':mernber l5, the member 33 being mounted to turn about the stud so that the radius member may Saune im@ Clifffeeeteneuler Peet-ieee, The .f course-indicating member v2 1s pivoted to the outer end of the radius4 member. 5 and it has rigid therewith a bevel gear 6 which :meshes with a'bevellgear1T-ena shaft-8 longitudinally ot thek radius member, the 'inn-er endl ofthe shaft being jour-naled {in-the `memleer'33T-and having fast thereon' `a i'loevell Jgear 19f which meshes with .a bevel-='gear`-10thatisgnotatably mounted onthemember. 33 whichcarriesthe indicator 3. Wfithf this construction the swinging voffl `the course-indicating "member 2"about its pvot at the endV otgt'he` radius ar-m A5 will 4'giver-a Icorresponding"turning movement the indicator 'inenber'vso that the indicator member v3 Wi-llj always indi-@ate -on the compass member 1 they-direction ott'he course-indicating member -"l`he abovedescrifbed. connection between the indicator -mem-ber and the foourseindieating member 2 is substantially they same as that .shown my above-mentionedpatent Tflie present invention relates to a `novel way of1r-1ountingV :the base @so that itfcan connected to a holder or carriageA 13. by

- 'is therein-'showin 'as'adjus't'a'bly 'mounted' on aboard orjsuplport 17-on which the Qcli'artvlyS may Jbe placed. Said' carriage 'or holder 1.13 will`r preferably vbefarraigedjv to be adjusted longitudinally ogffthefboarld so that-the carriagezcan be movedfrom oneend` tothe otlllieiio Ethe board. "The holder or carriage 13' is shown as sustained byv a "slideV 19 which is slidably mounted on a; ro'dtorf guide V20 extending along', onel edgey of -the) vboard .and

liereinfsholvvn carried-by ears` 21 secured to the jbozitrd.l suitable meanslmay be employed 'fori 'clamping' the), slide 19', to 'y the guide 10'6120' inleliy' adjusted Posities# v`haveherein shown saidY slidefas vpro!vided .with tlie'l split: hub 323 embraces ythe rod 20 .and havefprovided 'the clamping screw/22 for. claim` lng the hubft'o the rod.

The holderor carriage'lB is herein shown as adjustably mounted "on the Slide.` Said slide is provided. with the ways or guides el iny which the`l holder is received, and the latter is provided with a rslot 25 through .which extends a clamping screw 26 by which the holder is firmly clamped in adjusted .,positioli. This lateral adjustment provides for adjusting the holder or slide 13 toward and vfroinhthe edge of the boarda and the construction of the slide provides for adfjustingtheholdenl longitudinally of the board. y

The guide rod 20.isspaced from the edge 28 of. the boardtherebyleaving a space 29 so that if. the chart which is ybeingused has greater dimensions vthan the board, said chartniaybe inserted. through the opening,

as shownv invFigJQ.v

using-fthe device the chart will' be placedhon. the board and the compass-indi,- .eatingfmemberflwill: thenibe oriented Iso that the north and south marks thereonwill y j-usting the compass member 1 until1 the north and south marks thereon coincide with the direction of, the indicator 3. yAfter the compass member has thus 'been'. adjusted it; vwill be 'clamped in' adjustedfposition by tightening the clamping nut 331-.' vThe de'- vice is then ready for'use.

o Iffjitlis-desired to determine the direction between the two points a ando?) on the cha-rt, thenvtlie holder or carriage 13 will be ad'- justed'so that saidfpo'ints ai b willVV come 'withinlthe ran-geo-f'moveinentofthe courseind-icating'v member f2. j' Said .member will then be .movedso thatfit will lie on the'chart with. one edge .thereof touching. bothfof" the points e and'b, as seen in full lines, Fig. 1. The reading ofgthe ypointer 3` von thecompass Amember '1 Livill give the directionfbetween thepoints @and b. 1f, after'determiningthe 'direction between the 'pointsarl andi?) 'it' is desired tov determine the directionfbetween two-l other poi'nts c and d; which :are outside: of *the range ofI the .radius larm 5 .when the compiSS member is yin the full line, .positicrt Fie', i 15. it W'll only. be, Hesse saryy to swing the arms', la` about their pivots 1.5 Soga'stogbrng theconiplss member into a new.. pesition. in.. which' the. two .mints 0 and d cranbe neac'lned by the course-indicat- 'H/s member 2.,' as .Shewn in dotted. lines., .Fig- 1? and then .te applysaid,course-indicating. member tothe two points. and realgthe posi- 'tion of.' thefindicetn'g membery', aSjabQv-e described.'Y Y Th .Swingnelofthe armsl4=.,andrhe 0.011- sequent Ibodily movement of the'v ycompass member into the dotted line position does not change the setting of the compass member because the north of the compass member will alwayspoint in the same direction in all positions of the arms 14:.

If a still greater range of movementis desired, then the carriage 13 can be adjusted on the slide 19 or the slide and carriage maybe adjusted longitudinally of thero'd 20 and neither of these adjustments will dis,- turb or affect the setting of the compass member. By means of these various adjustments the direction between any' two points on the chart may be 'determinedfby simply bringing the course-indicating member into position so that one edge thereof extends from one to the other of said points and then reading the comp-ass member.

I claim:

1. In a course protractor, the combination with a. board fo-r supporting a chart, vof a slide carried by said board at one edge thereof and adapted to move longitudinally of the board, a carriage or holder secured to said slide for adjustment at rightangles to the movement of the slide, a pair .of parallel arms pivotally connected at one end to said carriage, a compass member to which the other ends of said arms are pivoted, a

radius arm extending from the compass member, a course indicating member pivoted to the radius arm, and means for indieating on the compass member the direction of the course-indicating member.

2. In a course protraotor, the combination with a board for supporting, a Chart, of a carriage adjustably mounted on the board, a pair of parallel arms pivotally connected at one end to'said carriage, a base member said stud, and bevel gears connecting said t shaft with said course-indicating member and pointer, respectively,

In testimony whereof I have signed my name to this specification.

JOHN F. COLE.

Copies of this patent may be obtained for ve cents each; by addressing the Commissioner of Patents,

. Washington, D. C. 

